Subject: ADRC: 717A Dear Bryan and Tom, I am writing in connection with your abstract for the upcoming Washington DC ADRC: 'A novel Sex-lethal germline promoter?' You mention a new Sxl allele, SxlfPS1, and say Most useful was SxlfPS1, a 4.5 kb intragenic deletion generated by mobilization of a P-element in exon 2. Could you tell me the progenitor strain for SxlfPS1 so that I can record its provenance accurately? Thank you for your help, with best wishes, Rachel. PS: Bryan's email address is not in FlyBase, so I'm sending it to both of you at Tom's address. Subject: Re: ADRC: 717A RE >Most useful was SxlfPS1, a 4.5 kb intragenic deletion generated by >mobilization of a P-element in exon 2. Could you tell me the progenitor >strain for SxlfPS1 so that I can record its provenance accurately? Dear Rachel, Well, let's see. I'll have to make up a name. Let's call it SxlM1,fPw+c. That is a PlacW insertion into exon 2 that is a null. But perhaps I should point out that both SxlfPS1 and SxlM1,fPw+c are on a SxlM1 background (that's a gof 9.5 kb roo insertion between exons 3 and 4, hence it is still present in its original form in fPS1). Regards, Tom Cline